Javier Alzueta Rodríguez

Factors Predicting and Having an Impact on the Need for a Permanent Pacemaker After CoreValve Prosthesis Implantation Using the New Accutrak Delivery Catheter System

OBJECTIVES The purpose of this study was to evaluate the need for a permanent pacemaker after transcatheter aortic valve implantation with the CoreValve prosthesis (Medtronic, Inc., Minneapolis, Minnesota) using the new Accutrak delivery system (Medtronic, Inc.). BACKGROUND The need for a permanent pacemaker is a recognized complication after transcatheter aortic valve implantation with the CoreValve prosthesis. METHODS Between April 23, 2008 and May 31, 2011, 195 consecutive patients with symptomatic aortic valve stenosis underwent transcatheter aortic valve implantation using the self-expanding CoreValve prosthesis. In 124 patients, the traditional delivery system was used, and in 71 patients, the Accutrak delivery system was used. RESULTS There were no significant differences in baseline electrocardiographic characteristics between the traditional system and the Accutrak patients: PR interval: 153 ± 46 mm versus 165 ± 30 mm, p = 0.12; left bundle branch block: 22 (20.2%) versus 8 (12.7%), p = 0.21; right bundle branch block: 21 (19.3%) versus 8 (12.7%), p = 0.26. The depth of the prosthesis in the left ventricular outflow tract was greater with the traditional system than with the Accutrak system (9.6 ± 3.2 mm vs. 6.4 ± 3 mm, p < 0.001) and the need for a permanent pacemaker was higher with traditional system than with Accutrak (35.1% vs. 14.3%, p = 0.003). The predictors of the need for a pacemaker were the depth of the prosthesis in the left ventricular outflow tract (hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 1.08 to 1.34, p < 0.001), pre-existing right bundle branch block (HR: 3.5, 95% CI: 1.68 to 7.29, p = 0.001), and use of the traditional system (HR: 27, 95% CI: 2.81 to 257, p = 0.004). CONCLUSIONS The new Accutrak delivery system was associated with less deep prosthesis implantation in the left ventricular outflow tract, which could be related to the lower rate of permanent pacemaker requirement.

Improvement in hemodynamic response using a quadripolar LV lead.

The Quartet™ quadripolar lead (St. Jude Medical Inc., St. Paul, MN, USA) offers 10 different left ventricle pacing configurations that may further influence hemodynamic parameters compared to traditional bipolar pacing configurations. The purpose of this study was to evaluate whether pacing from additional quadripolar lead vectors could enhance cardiac output (CO).

Radiofrequency Catheter Ablation of Ventricular Tachycardia in Patients With an Implantable Defibrillator. Long-Term Follow-up

INTRODUCTION AND OBJECTIVES The frequent occurrence of ventricular tachycardia can be a serious problem for patients with an implantable defibrillator, and may necessitate adjuvant antiarrhythmic therapy or radiofrequency catheter ablation. We analyzed the long-term results obtained with this latter therapy in patients suffering from frequent or continuous ventricular tachycardia. PATIENTS AND METHOD Eighteen ablation procedures were performed in 11 patients who had a defibrillator implanted because of previous syncopal ventricular tachycardia. All were men, aged 67.64 (5.87) years; 10 patients had had a myocardial infarction 15.50 (5.08) years earlier, and one suffered from arrhythmogenic right ventricular dysplasia. RESULTS Electrophysiologically, treatment was initially successful in 8 patients (72.73%). After a follow-up period of 39.10 (24.70) months, the number of defibrillator discharges decreased significantly in all patients, from 52.82 (35.73) to 0.64 (1.03) (P=.001). During follow-up, ventricular tachycardia occurred in nine patients. In five, it took the same form as the ablated ventricular tachycardia. Six patients needed additional ablation procedures: two because of initial failure, three because of recurrence, and one because a different ventricular tachycardia occurred. In addition to the good electrophysiological results obtained, long-term clinical evolution was favorable in all patients. CONCLUSIONS Radiofrequency ablation successfully disrupts frequent or continuous ventricular tachycardias and significantly reduces the defibrillator discharge rate even when ablation has failed electrophysiologically. It is particularly useful in these latter critical situations, in which other therapies are not sufficiently effective. Because our patients mainly had ischemic heart disease and were highly susceptible to new arrhythmias during follow-up, ablation complemented rather than replaced the implantable defibrillator.